Add a countQuantity element to the MeasureReport to support decimal-valued counts: MeasureReport.group.pouplation.countQuantity Quantity 0..1 Size of the population as a quantity | The number of members of the population, specified as a quantity to support identifying units, as well as to support some composite measure calculation use cases where the resulting count of the population is a decimal value. MeasureReport.stratifier.stratum.population.countQuantity Quantity 0..1 Size of the population as a quantity | The number of members of the population in this stratum, specified as a quantity to support identifying units, as well as to support some composite measure calculation use cases where the resulting count of the population is a decimal value. Add an invariant that if both count and countQuantity are populated, the value of countQuantity is equal to the value of count. In addition, add a Trial-Use Note that we are seeking implementer feedback on whether to generalize the count element itself (i.e. change the count element to a Quantity, a breaking change), or keep the approach of defining a new countQuantity element to maintain backwards compatibility). And finally, add the example provided in this JIRA ticket as an example of this usage (Patient-level linear combination composite): https://jira.hl7.org/browse/FHIR-41226